My Bluereader device won't show in ADE. My PC and bluereader are both authorised and I am launching the reader after opening ADE. Still now sign of device. Can anyone help?

I can't see my bluereader device in the ADE left window so can't transfer any books from ADE.  PC and Bluereader are authorised.  My device is a Kindle Fire which is supported by ADE.  Has anyone any suggestions, please?